1. Field of the Invention
The present invention relates to an apparatus for establishing a frame synchronization of received data, and more particularly, to a high-speed frame synchronizing apparatus which realize a high-speed operation and a quick establishment of a synchronization.
In PCM communications, transmission data must be correctly received on the receiving side. To realize this, a frame synchronizing signal is superposed over the transmission data, and the receiving side identifies phases of received data according to the frame synchronizing signal. Such a frame synchronization is generally adopted.
In this frame synchronization, a synchronizing operation must be carried out as quickly as possible, to shorten the time needed for establishing a synchronization.
2. Description of the Related Art
In the conventional frame synchronization, two methods are used, i.e., a synchronization detecting process is carried out for every bit; or a synchronization detecting process is carried out for every frame.
In the former method, the frame synchronizing signal can be detected within one frame period so that the synchronization can be quickly established.
However, the operating speed of various components in the synchronizing apparatus must be very high, and this is a problem which the present invention intends to solve.
In the latter method, the operating speed of the main components in the synchronizing apparatus may be rather low, but the frame synchronization takes a very long time. This is another problem which the present invention intends to solve.